1. Nombres de répresentations d'une permutation comme produit de deux cycles de longueur données;Boccara;Discrete Math.,1980
2. Introduction to Enumerative Combinatorics;Bóna,2007
3. Sorting permutations by block interchanges;Christie;Inform. Process. Lett.,1996
4. On Hultman numbers;Doignon;Journal of Integer Sequences,2007
5. A. Hultman, Toric Permutations, Master's thesis, Department of Mathematics, KTH, Stockholm, Sweden, 1999